I've never heard TOS or any episodic series described as an anthology, not in previous decades and not now. That term is used for Twilight Zone, The Outer Limits, etc. Every episode is not just a separate story but has new characters and new actors.

At most, you could also call American Horror Story an anthology series because each season is a separate story with different characters and premise. Anthologies are rare on TV. There's no point in saying "I want episodic Star Trek" and then referring to it by the wrong name.